Page:The Zoologist, 4th series, vol 5 (1901).djvu/237

Rh able to continue observing with more certain result in future winters.

In the ' Zoologist' for 1894, pp. 410, foll., Mr. O.V. Aplin had a short paper in which he clearly distinguished the autumn song of some birds—e.g. the Robin and the Chiffchaff (i.e. the song resumed after the moult, often feeble and imperfect)—from the winter song, which in some cases begins in November, and continues more or less regularly till breeding begins: this winter song (if I understood him rightly) he regarded as undoubtedly the beginning of the spring or breeding song. Dr. Häcker does not express himself quite so decidedly, and, on the whole, he seems disposed to take a different view: and as his remarks are interesting in several ways, and are the result (as he tells us in his preface) of twenty years' observation, I take leave to translate them here ('Der Gesang der Vögel,' p. 52):—

"In the renewal of song in autumn, when the Robin (Erythacus rubecula), the Blackbird (Turdus merula), and the Chiffchaff (Phyllopneuste rufa) are conspicuous, we have to do, in distinction from the summer song, exclusively with a kind of voice-play (Spielstimmung), as Darwin pointed out; in fact, with a psychical condition, which, for example, is to be found in adult dogs, which delight in play, and invite their masters to join them.

"The same holds good in part for those birds which, in the middle of winter—i.e. long before the beginning of the breeding season—let us hear their song. To these belong the Wren (Troglodytes parvulus), whose breeding falls in April, and the Dipper (Cinclus aquaticus), which normally has its first brood in April, and its second in June. Here we have to do with birds which are exceptionally robust, and whose perfect adaptability to a winter climate is plain from the fact that here at least (i.e. in Breisgau) they are true residents with a limited winter range. A few hours of winter sunshine is enough to produce in these birds that increase of bodily and psychical comfort which leads to the use of voice-play.

"I have attempted above to explain the meaning of the different sexual cries in connection with the preservation of the species. Only in a few cases—namely, in those of the autumn and winter song of a few resident species—are we unable to assign to song a positive importance for the preservation of species or individual.